please help

1- Assume that the sequence of rv's {Xn} have Gamma distributions with XM ~ P(n,). (a) Using properties of the Gamma distribution, show that (i.e. ex- plain why) {If/\"5 V171} converges in distribution to Z which has a standard normal distribution, i.e. Z N NH], 1). (b) Explain why 2);\" has a X2 distribution and identify the number of degrees of freedom